High pitch whirling noise from engine bay

[Tiger Magnet]

Hiya. i have an f reg mk1b and since saturday afternoon a high pitch whirling noise has started coming from the engine bay. at first it sounds like it is coming from the tvis area but after closer inspection it could be coming from the alternator area!!! belts look ok but im no expert!! The high pitch noise gets faster when accelarating even if not moving so assume its not gearbox. any ideas would be much appreciated. thanks

[Lauren]

Bearing on the way out on a pulley or idler?

[Tiger Magnet]

ooohh. could be. thanks mate. ill check it out. sounds like it could be a fun job

[un1eash]

Remove the alternator belt and start the car. Will help narrow it down as if the noise goes its either the alternator bearing, water pump or the bottom pulley delaminated.

[Tiger Magnet]

thanks for the help guys. i sprayed the alternator and belts with wd40 last night. left it to soak over night and after starting the car this morning the noise vanished after 10 seconds. so know that was the problem area. will wait for noise to come back before replacing alternator and belt

[pk_090]

Sometimes i noticed when i did some work on mine a few weeks ago that my alternator and belt were not 100% square, this cause a squeak only on start-up. I have re straightened and then greased everything up and no more squeal now.
Alex

[jimi]

I really hope you didn't spray the alternator belt with WD40! WD40 is a lubricant, the belt is supposed to grip not slip

[Tiger Magnet]

no sorry i meant i sprayed the alternator with wd40. i used silicone spray on the belts!!!